package com.my.algorithmlearning.leetcode;

import org.springframework.util.Assert;

import java.util.Arrays;

/**
 * @ClassName Medium_64_MinPathSum
 * @Description 题解：https://leetcode.cn/problems/minimum-path-sum/solution/zhong-deng-64-zui-xiao-lu-jing-he-dong-t-9wyz/
 * @Author wanghaiwei
 * @Date 2023/3/7 11:03
 */
public class Medium_64_MinPathSum {

    public int minPathSum(int[][] grid) {
        if (grid == null || grid.length == 0) {
            return 0;
        }
        if (grid[0].length == 0) {
            return 0;
        }
        int m = grid.length; //行
        int n = grid[0].length; //列
        int[][] dp = new int[m][n];
        dp[0][0] = grid[0][0];
        for (int i = 1; i < m; i++) {
            dp[i][0] += dp[i - 1][0] + grid[i][0];
        }
        for (int j = 1; j < n; j++) {
            dp[0][j] += dp[0][j - 1] + grid[0][j];
        }
        for (int i = 1; i < m; i++) {
            for (int j = 1; j < n; j++) {
                dp[i][j] = Math.min(dp[i - 1][j], dp[i][j - 1]) + grid[i][j];
            }
        }
        return dp[m - 1][n - 1];
    }

    public static void main(String[] args) {
        Medium_64_MinPathSum solution = new Medium_64_MinPathSum();
        int result = solution.minPathSum(new int[][]{{1, 3, 1}, {1, 5, 1}, {4, 2, 1}});
        Assert.isTrue(7 == result, "Input: grid = [[1,3,1],[1,5,1],[4,2,1]]计算错误，预期7，实际：" + result);
        result = solution.minPathSum(new int[][]{{1, 2, 3}, {4, 5, 6}});
        Assert.isTrue(12 == result, "Input: grid = [[1,2,3],[4,5,6]]计算错误，预期12，实际：" + result);
    }
}
